Absorbent articles, such as sanitary napkins, panty liners, and incontinence pads that are designed to absorb and retain liquids and other discharges from the human body and to prevent body and clothing soiling, having various different constructions are well known.
The current tendency has been to develop absorbent articles such as sanitary napkins which are increasingly thinner and conform better to the body. Recently, efforts have been directed to developing thinner sanitary napkins which have the capacity to absorb and contain medium to high menstrual discharges. Previously, such discharges could only be handled by relatively thick sanitary napkins. Examples of thin sanitary napkins having capacities great enough to handle medium to high menstrual flows are disclosed in U.S. Pat. Nos. 4,950,264 and 5,009,653, issued to Osborn, on Aug. 21, 1990 and Apr. 23, 1991, respectively.
One of the main objectives in developing absorbent articles is to utilize the entire capacity of the absorbent article. The utilization of the capacity for absorption of menses and other bodily exudates in the thin sanitary napkins described in the Osborn references is achieved at least in part by the presence of a "wipe acquisition sheet" that distributes the exudates more evenly over the underlying absorbent core. In general, products that are not provided with a structure like the wipe acquisition sheet described in the aforementioned patents, typically distribute liquids in a circular pattern, resulting in liquids reaching the longitudinal side edges of the absorbent article before the end regions of the absorbent article are utilized. When liquids come near the longitudinal side edges of the absorbent article, the chance for leakage from the sides of the product increases, despite available absorbent capacity in the end regions of the absorbent article.
In the past, a number of efforts have been made to direct exudates in an attempt to utilize more of the absorbent capacity of an absorbent article. A number of these efforts have used absorbent means or densification of absorbent means. Some of such efforts are described in U.S. Pat. No. 4,678,453 issued Jul. 7, 1987 to Holtman and U.S. Pat. No. 4,624,666 issued Nov. 25, 1986 to DeRossett, et al. Absorbent articles which use absorbent means to direct fluid flow, however, are typically subject to the disadvantage that the absorbent means will tend to become saturated and interfere with its fluid directing capabilities.
Another series of patents teaches the use of baffles, barriers, and transfer members for liquid transport. For instance, U.S. Pat. No. 4,029,101 issued Jun. 14, 1977 to Chesky et al. discloses using an elongated baffle near the base of the pad. U.S. Pat. No. 3,736,931 issued Jun. 5, 1973 to Glassman discloses using a moisture impervious layer in the pad. However, in both of these examples, liquids may wick laterally before reaching the baffle or the moisture impervious layer. This may tend to cause side failure (or side leakage), particularly when the pad bunches during wear. In such cases, the barrier or transfer member may be disturbed by the bunching of the pad, and body fluids may circumvent the barrier or transfer member and flow directly toward the longitudinal side edges of the product.
Thus, a need exists for an absorbent article, such as a sanitary napkin that has an improved means for directional fluid distribution that distributes bodily exudates so that the exudates will not reach the longitudinal side edges of the absorbent article before reaching the end regions of the article.
It is, therefore, an object of the present invention to provide an absorbent article such as a sanitary napkin with a means for enabling the entire absorbent capacity of the sanitary napkin to be utilized before liquids reach the longitudinal side edges of the napkin.
It is another object of the present invention to provide a generally thin, flexible sanitary napkin that conforms to the wearer's body.